This invention relates generally to disposable absorbent articles, e.g., diapers for children/infants and briefs for adults, and more specifically to articles of that type which are can be manufactured very efficiently and economically and which exhibit good protection from leakage, good fit and comfort.
Disposable absorbent articles, such as infant/child diapers and adult incontinent briefs, are designed to absorb and contain body waste, e.g., urine and/or feces, to prevent such waste from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. Many such diapers/briefs are commercially available. Moreover, the patent literature is replete with examples of various diaper/brief constructions and methods of manufacturing them.
For example, In U.S. Pat. No. 4,764,234 (Smits, et al.), which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein, there is disclosed a method of manufacturing an absorbent pad for utilization as a diaper or an adult incontinent brief. The method entails providing a moving web of material forming sequential backing sheets for the article. Nozzles are utilized to apply a pair of continuous bands of adhesive to the back sheet of the pad, prior to its assembly. The nozzles eject the adhesive onto a moving web which makes up the backing sheet and are shifted sideways during their extrusion of adhesive from a first location to a second location. This action generates a pair of non-linear bands of adhesive on the backing sheet. The nozzles are again shifted from their second location to their original first location. The elastic band is not shifted when the nozzles are, thus effectuating securement of the elastic bands only on the portions of the backing sheets where the adhesive was applied at the first location. The sequentially located sheets are cut on opposite marginal side to form leg cut-out areas, whereupon only those portions of the elastic bands at the center of each of the leg cut-out areas contract to form a gather thereat.
U.S. Pat. No. 4,764,242 (Gressick et al.), which is also assigned to the same assignee as this invention and whose disclosure is also incorporated by reference herein, discloses a machine for manufacturing a diaper or brief like that disclosed in the aforementioned Smits et al. patent.
U.S. Pat. No. 4,795,451 (Buckley), which is also assigned to the same assignee as this invention and whose disclosure is also incorporated by reference herein, discloses a disposable absorbent pad for use as a baby diaper or an adult incontinent brief wherein the backing sheet of the diaper has a pair of continuous bands of adhesive arranged in a stepped generally longitudinal configuration thereon. An elastic band is disposed over the mid-portion of the adhesive being stepped to the side, out of contact with the elastic. When the pads are cut in the assembly process, only that portion of elastic in contact with the adhesive causes the pad to gather. The remaining end portions of the adhesive bands are secured to the intermediate layer of absorbent fluff material, helping it remain in place, and act as a fluid barrier on the sides of the absorbent pad.
U.S. Pat. No. 4,804,379 (Toth et al.), which is also assigned to the same assignee as this invention and whose disclosure is also incorporated by reference herein, discloses a disposable absorbent pad for utilization as a diaper or adult brief. The pad is an absorbent member covered on one side by a sheet of fluid impervious material, and on the other side by a pair of generally parallel strips of fluid impervious material overlapping the absorbent pad and the backing sheet, in the crotch area to prevent leakage of fluid from the absorbent pad in the crotch area. The pad includes a pair of opposed leg cut-outs each of which is elasticized by a linear elastic band.
In U.S. Pat. No. 5,439,459 (Tanji et al.), there is disclosed an arrangement of a disposable diaper in which there are provided elastic members extending not only along opposite side edges of an opening formed in a skin-contacting topsheet but also further extending beyond longitudinally opposite ends of the opening substantially to longitudinally opposite ends of the skin-contacting topsheet so that the opening may sufficiently rise up together with the skin-contacting topsheet to assure reliable introduction of excretions through this opening into a pocket space defined between the skin-contacting topsheet and a separately provided topsheet underlying the skin-contacting topsheet.
In U.S. Pat. No. 5,628,741 (Buell et al.), there is disclosed absorbent articles having an elastomeric member and an associated non-elastic web for improving the dynamic fit as well as containment characteristics. A portion of the nonelastic web coincides with at least a portion of the elastomeric member. The portion of the nonelastic web is mechanically prestrained to improve not only the extension of the elastomeric member, but also the heat-shrink contraction of preferred elastomeric members.
In U.S. Pat. No. 5,643,243 (Klemp), there is disclosed a disposable diaper having opposed leg cut-outs and unitary elasticized leg cuffs disposed on the interior surface of the diaper along the leg cut-outs.
In U.S. Pat. No. 5,643,377 (Juergens), there is disclosed a process for making a wearable, absorbent article wherein two longitudinally extending barrier leg cuffs are attached to a chassis and the barrier leg cuffs are joined to the article so that they are directed inwardly toward a longitudinally extending centerline in the first waist region of the article and directed outwardly away from the longitudinally extending centerline in the second waist region of the article. The article is made by a method that entails first attaching the cuffs in the first waist region and then in the second waist region in one embodiment and, in another embodiment, being attached in the second waist region first and then in the first waist region of the article. The method also entails attaching the barrier leg cuffs to the article outboard of the longitudinally extending centerline in both the first waist and second waist regions of the article and wherein the barrier leg cuffs are joined partially to the article in the crotch region.
In U.S. Pat. No. 5,649,919 (Roessler et al.), there is disclosed an absorbent article which has a lateral width, a longitudinal length, longitudinally extending side margins, a front waistband portion, a back waistband portion, and an intermediate portion which interconnects the front and back waistband portions. The article comprises a backsheet layer and an absorbent retention portion superposed on the backsheet layer. A liquid permeable topsheet layer is superposed on the retention portion to sandwich the retention portion between the topsheet layer and the backsheet layer. An elasticizing means form elasticized gathers at leg opening portions of the article. The elasticizing means include a front set of laterally opposed, longitudinally extending leg elastic members located in the article side margins in at least the intermediate portion of the article. The front elastic members are arranged asymmetrically with respect to the article length and have a selected offset toward the front waistband portion of the article. A back set of laterally opposed, longitudinally extending leg elastic members are constructed separate from the front set of elastic members and are located in the article side margins in at least the intermediate portion of the article. The back elastic members are arranged asymmetrically with respect to the article length and have a selected offset toward the back waistband portion of the article.
In U.S. Pat. No. 5,776,121 (Roe et al.), there is disclosed absorbent articles, such as disposable diapers, having two waist regions and a crotch region. The absorbent articles comprise a liquid pervious topsheet, a liquid impervious backsheet, an absorbent core disposed between the topsheet and the backsheet, and a pair of longitudinally extending barrier cuffs. The barrier cuffs are formed from a lateral extension of the topsheet and the backsheet in at least the crotch region of the absorbent article using material that is normally discarded when the crotch area is formed. A cuff area is defined by pairs of laterally opposed cuts in the lateral extension of the topsheet and the backsheet. The cuff area is then folded and joined to the topsheet or other underlying structure to form the barrier cuff and an optional gasketing cuff.
In U.S. Pat. No. 5,904,675 (Laux et al.), there is disclosed an absorbent article has a longitudinal length dimension, a lateral cross dimension, a front waistband portion, a back waistband portion and an intermediate portion which interconnects the front and back waistband portions. The article includes a backsheet layer having a pair of laterally opposed side margins, with each side margin having an outwardly concave, terminal side edge contour located at appointed leg opening regions in an intermediate portion of each of the side margins. Each concave side edge contour has a selected longitudinal extent along the length dimension of the article. A liquid permeable topsheet layer is connected in superposed relation to the backsheet layer, and an absorbent body is sandwiched between the topsheet layer and the backsheet layer. A separate, elasticized and gathered leg gusset is connected to the article along each of the appointed leg opening regions, and each leg gusset is configured to extend beyond and to bridge between opposed, spaced-apart portions of an associated one of the concave side edge contours of the backsheet layer.
In U.S. Pat. No. 5,906,603 (Roe et al.), there is disclosed a disposable absorbent article including a topsheet, a backsheet, and an absorbent core having a pair of opposed longitudinal edges. The absorbent article includes a leg cuff extending at least laterally outwardly from each opposed longitudinal edge. Each leg cuff has a proximal edge, a distal edge and an elasticized region disposed between the proximal edge and the distal edge. The elasticized region has an inner edge, an outer edge and a width. The proximal edge of each leg cuff extends generally longitudinally along and adjacent to at least a portion of one of the opposed longitudinal edges and the distal edge of each of said leg cuffs is disposed laterally outwardly from the proximal edge. Each leg cuff includes an inner bond disposed adjacent at least a portion of the proximal edge of each leg cuff. An outer bond is spaced laterally outwardly from the inner bond, the spacing between the inner bond and said outer bond defining a leg cuff base width. Each leg cuff also includes an inner wall that extends upwardly and laterally outwardly from the inner bond to the inner edge of the elasticized region having a first height, and an outer wall that extends upwardly and laterally inwardly from the outer bond to the outer edge of the elasticized region having a second height. An elastic element is disposed in the elasticized region of each leg cuff and is provided generally parallel to the wearer""s skin.
In U.S. Pat. No. 6,010,586 (Suprise), there is disclosed a disposable absorbent article which defines a first side portion, a second side portion, and a longitudinal centerline between the side portions. The absorbent article comprises an outer cover and an absorbent insert which is connected to the outer cover. The outer cover comprises a first side panel which is located in the first side portion of the absorbent article and a second side panel which is located in the second side portion of the absorbent article. An edge of the first side panel is connected to an edge of the second side panel to provide a seam which extends along the longitudinal centerline between the side portions of the absorbent article. The opposite waist regions on each side panel are configured to encircle the legs of the wearer and releasably engage together about the hips of the wearer. The disposable absorbent article has an aesthetically pleasing garment-like appearance and is readily refastenable about the hips of the wearer.
While the prior art disposable absorbent diapers and briefs may be generally suitable for their intended purposes, they still leave much to be desired from the standpoints simplicity of construction and of ease and economy of manufacture. For example, some of the aforementioned patents require cutting away portions of the article to form the leg cut-outs or openings. This can be a somewhat complex undertaking and is also wasteful of materials and resources, e.g., the cut away material is scrap which must be removed and discarded (all of which likely result in higher production costs). Moreover, in order to ensure that there will be no leakage around the leg openings, such openings are typically gathered by use of elastic materials, e.g., threads or beads, applied thereto. or standing leg cuffs or other upstanding elasticized wall-like barriers can be provided. Either of these approaches can also present a somewhat complex, and production-cost-increasing undertaking. While eliminating elasticized leg openings would inherently lower the production cost of the diaper, it would likely result in the increased tendency of the diaper/brief to leak, while also be ill-fitting. Moreover, such a device would likely be somewhat uncomfortable due to its lack of a close conforming fit to the wearer""s anatomy. Thus, a need presently exists for a diaper/adult brief that is simple in construction, can be manufactured economically and efficiently without wastage, and which provides a good fit, resistance to leakage and wearing comfort. It is to those ends that this invention is directed.
A disposable absorbent article, e.g., a diaper or an adult brief, arranged to be worn by a wearer to trap and collect waste materials and a method of economically manufacturing the article.
The article basically comprises a front section, a rear section and an intermediate section. The front section, e.g., either one or two mirror-image panels, is a generally planar member formed of a flexible material, e.g., a non-woven material, a non-woven material and a poly-film adhesively secured together, a poly-laminate, a poly-film, etc. The panel(s) of the front section has(have) a top edge, a somewhat concave bottom edge and an opposed pair of side edges. The rear section is preferably formed of the same material as the front section and may also be a single panel or a pair of mirror-image panels that have(has) a top edge, a somewhat convex bottom edge and an opposed pair of side edges, said intermediate section being an elongated member formed of a flexible material having a pair of side edges and an pair of end edges.
The intermediate section is an elongated member formed of a flexible material, e.g., a moisture pervious cover-stock layer, a moisture barrier layer and an absorbent core interposed therebetween. The intermediate section may optionally include a fluid transfer layer interposed between the cover-stock layer and the core. In any case the intermediate section includes a pair of elongated side edges and an pair of end edges.
The intermediate section is fixedly, e.g., adhesively, secured to said front section intermediate the front section side edges adjacent one of the intermediate section""s end edges. The other end of the intermediate section is similarly fixedly secured to the rear section intermediate the rear section""s side edges.
The front and rear sections are arranged to be releasably secured to each other to mount the article on the wearer, with a first portion of the concave bottom edge of the front section adjacent one side edge of the front section, one side edge of the intermediate section, and a first portion of the convex arcuate bottom edge of the rear section adjacent the one side of the front section forming one leg hole for accommodating one leg of the wearer. In a similar manner a second portion of the concave bottom edge of the front section adjacent the other side edge of the front section, the other side edge of the intermediate section, and a second portion of the convex arcuate bottom edge of the rear section adjacent the second side of the front section forms the other leg hole for accommodating the other leg of the wearer.
The intermediate section is elasticized, e.g., includes tensioned elastic threads extending along the respective sides of the intermediate section to form to a pair of upstanding walls conforming to the crotch of the wearer. The intermediate section is arranged to absorb and trap waste material therein, and may optionally include a pair of standing leg gathers or cuffs for additional protection from leakage of waste materials out of the crotch area.
To facilitate the releasable mounting of the article on the wearer the article includes at least two fastening members, one on each side of one of the article""s sections, e.g., the rear section. The fastening members may be adhesive tapes or multi-hook tabs. In addition the front panel may include landing zones, e.g., (BOPP) Bi-axially orientated Polypropylene film or a multi-loop or plush material to be releasably engaged by fastening tapes or multi-hook tabs.
The method aspect of this invention entails manufacturing plural disposable absorbent articles like those described above. The method basically comprising the steps of providing a series of sheet units along an assembly feed line. Each of the sheet units comprises an area forming the front section of a leading article, e.g., diaper, to be manufactured and the rear section of the next succeeding article to be manufactured. The front and rear sections of each of the sheet units merge together at an interface line. Each interface line forms the top edge of respective ones of the front and rear sections of the articles being manufactured.
A series of said intermediate sections are also provided along another assembly feed line. Each of the intermediate sections has a leading end portion and a trailing end portion and a pair of long sides along which respective tensioned elastic lines are provided.
The method further entails conveying a first one of the sheet units into engagement with the leading end portion of a first intermediate section of the series of intermediate sections and fixedly securing, e.g., adhesively securing, the sheet unit thereto. A second one of the sheet units is conveyed into engagement with the trailing end portion of the first intermediate section of the series of intermediate sections and fixedly secured, e.g., adhesively bonded, thereto. Then the interface lines of the first and second sheet units are severed therealong to form one of the articles and to separate it from the assembly line.
In accordance with one preferred embodiment of the invention the area of each unit defining the front section of the article and the area of that unit defining the rear section of the article are of complementary shape.